Display element, portable equipment and imaging device

ABSTRACT

An electronic device includes a display unit that includes a flexible display element which displays an image on a front surface thereof, and a member which is placed facing a rear surface opposite to the front surface of the flexible display element, in which the member applies tension to the flexible display element when the flexible display element is unfurled.

The present application is a Divisional Application of U.S. patentapplication Ser. No. 12/002,753, filed on Dec. 19, 2007, and claimsbenefit of priority from Japanese Patent Application No. 2006-343267,filed on Dec. 20, 2006, the entire contents of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a display element, portable equipment,and an imaging device which have high portability, a high compactifyingcapability, and high operability.

2. Description of the Related Art

Numerous kinds of portable equipment using flexible display elementswhich can be reduced in size when carried have been proposed. Forexample, like a roll-up display disclosed in Japanese Patent ApplicationLaid-Open No. H09-216465, some kinds of portable equipment enableviewing of images recorded by thermal heads. According to JapanesePatent Application Laid-Open No. H09-216465, a recording medium pulledout of the main body of equipment is flexible like paper and does nothave flatness alone. Therefore, as is evident from the drawings ofJapanese Patent Application Laid-Open No. H09-216465, according to thecharacteristics, the recording medium has to be held with both hands tokeep the flatness.

As disclosed in Japanese Patent Application Laid-Open No. 2003-250074and Japanese Patent Application Laid-Open No. 2003-274250, some kinds ofportable equipment have flexible displays and have the followingdrawbacks: when the strength of a display is increased to keep the shapeof the display pulled out of the main body of equipment, the strengthbecomes a resistance to rolling when the display is stored. Thus it isdifficult to roll up the display. On the other hand, when theflexibility of the display is increased to facilitate rolling, the shaperetention of the display decreases. In order to keep the flatness, it isnecessary to hold a gripping portion on the opposite side of the mainbody of equipment, thus operability is hard to obtain.

Further, Japanese Patent Application Laid-Open No. 2000-19980 proposes adisplay body that is curved when pulled out (claim 1 and paragraph[0022] in Japanese Patent Application Laid-Open No. 2000-19980). A smallcurvature causes an insufficient strength and the curvature has to beincreased to obtain a sufficient strength. As a result, a curved displaymay be viewed and the display may not have a designed aspect ratio.

Furthermore, Japanese Patent Application Laid-Open No. 2000-10086 andJapanese Patent Application Laid-Open No. H09-134132 propose displayunits that are surrounded by frames keeping the flatness of the displayunits. Since the frames cannot be rolled up, a problem arises in storingthe frames. Thus such equipment is stored in a complicated manner andthe size reduction is limited.

In Japanese Patent Application Laid-Open No. 2004-118803 and JapanesePatent Application Laid-Open No. 2004-109382, displays are just foldableand thus the degree of size reduction is smaller than that of a roll-updisplay.

As described above, in related art, numerous kinds of equipment usingflexible display elements are proposed which are reduced in size whencarried. However, all of the methods are defective in ease of rolling(compactifying capability) and retention of flatness (operability)during periods of use.

SUMMARY OF THE INVENTION

An object of the present invention is to propose a flexible displayelement, portable equipment, and an imaging device which have highportability, ease of rolling, and retention of flatness during periodsof use.

In order to attain the object, a display element according to a firstaspect of the invention is a flexible display element capable of beingrolled up and unfurled, including a back plate covering the back side ofthe display element, wherein the back plate comes into contact with theback side of the display element when the display element is rolled up,and at least a central portion of the back plate is separated from thedisplay element to support the display element in a flat shape when thedisplay element is unfurled.

According to the display element of the first aspect of the invention,the display element and the back plate can be rolled up and carried witha simple configuration of the display element and the back plate, andthe display element can be supported in a flat shape when unfurled. Thusit is possible to provide a flexible display element having highportability, ease of rolling, and retention of flatness during periodsof use.

In order to attain the object, a portable equipment according to asecond aspect of the invention is a portable equipment including aflexible display element capable of being rolled up and unfurled, whichincludes a back plate on the back side of the display element, whereinthe back plate comes into contact with the display element when thedisplay element is rolled up, and the back plate is bent such that atleast a central portion of the back plate is separated from the displayelement due to a bend when the display element is unfurled, and theflatness of the display element is kept by a structure made up of thedisplay element and the back plate when the display element is unfurled.

According to the portable equipment of the second aspect of theinvention, the back plate is provided on the back side of the flexibledisplay element. The back plate comes into contact with the displayelement when rolled up, and at least the central portion of the backplate is separated from the display element due to a bend (deformation)when unfurled. Since the strength of the display element is kept by theback plate, a sufficient strength can be obtained by the bend. Thus evenin the presence of a large bend, the display element is not bent and adesigned aspect ratio can be obtained on display.

In order to attain the object, a portable equipment according to a thirdaspect of the invention is a portable equipment including a flexibledisplay element capable of being rolled up and unfurled, furtherincluding a back plate on the back side of the display element, whereinthe back plate reduces a resistance to a rolling movement by removing alateral pressure in the planar direction of the display element todecrease shape retention of the display element when the display elementis rolled up, and applies a lateral pressure to the display element tokeep the shape of the display element flat when the display element isunfurled.

According to the portable equipment of the third aspect of theinvention, the back plate can obtain shape retention when the displayelement is pulled out, and can reduce a resistance when the displayelement is rolled up. The back plate applies a lateral pressure incontact with both sides of the display element when bent, and removesthe lateral pressure when rolled up, and a clearance is generatedbetween the back plate and at least one of the sides of the displayelement, thereby reducing a resistance when the display element isrolled up.

According to a portable equipment of a fourth aspect of the invention,in one of the second and third aspects, the back plate is V-shaped incross section with the central portion separated from the displayelement due to a bend when the display element is unfurled.

The portable equipment of the fourth aspect of the invention enables theback plate to have a highly stable shape and facilitates processing andproduct inspection.

According to a portable equipment of a fifth aspect of the invention, inthe second to fourth aspects, the back plate has a ridge member to makea shape with a plurality of ridges by a plurality of bent portionsseparate from the display element, so as to form a space surrounded bythe display element and the back plate when the display element isunfurled.

According the portable equipment of the fifth aspect of the invention,the display element is unfurled and placed on a table and the like withhigher stability.

According to the portable equipment of a sixth aspect of the invention,in the second to fourth aspects, the back plate has one end fixed on theback side of the display element.

According to the portable equipment of the sixth aspect of theinvention, the back plate has one end fixed on the back side of thedisplay element, thereby reducing rattling caused by unsteadiness duringtransportation.

In order to attain the object, an imaging device according to a seventhaspect of the invention is an imaging device including at least a takinglens and a shooting part, the imaging device further including: a mainbody substantially shaped like one of a cylinder and a polygon, and adisplay element stored in the main body when carried, and pulled out ofthe main body when used to display a photographed image or a reproducedimage, wherein the display element has a flatness keeping mechanism forkeeping flatness when the display element is pulled out, and theflatness keeping mechanism keeps a predetermined positional relationshipand shape relative to the main body by applying a restraining force tothe pulled out display element, and releases the restraining force whenthe display element is stored in the main body.

According to the imaging device of the seventh aspect of the invention,shooting is enabled when the main body is held with one hand and thedisplay element is pulled out with the other hand. At this moment, sincethe shape of the display element is kept by the flatness keepingmechanism, an operation can be performed with one hand holding the mainbody. Further, the display element can be easily rolled up when stored.The display element is pulled out to the left or the right when viewedfrom the back side of the main body. Considering that the shooting partis operated with the right hand of a photographer it is preferable topull out the display element to the left in view of operability.

According to an imaging device of an eighth aspect of the invention, inthe seventh aspect, the flatness keeping mechanism is a back platecovering the back side of the display element, the back plate comes intocontact with the back side of the display element when the displayelement is rolled up, at least a central portion of the back plate isseparated from the display element to support the display element in aflat shape when the display element is unfurled, a pull-out slot for thedisplay element on the main body is formed to have a shape which issubstantially identical to a cross-sectional shape of the unrolled backplate, and to have a clearance formed on a portion facing a surface ofthe display element.

According to the imaging device of the eighth aspect of the invention,the clearance of the pull-out slot of the main body does not bring thesurface of the display element into contact with the pull-out slot,thereby preventing scratches. Additionally, the bent portion of the backplate is not flattened by the pull-out slot and thus the positionalrelationship between the main body and the display element can be kept.When the main body is held, the shape of a base (near the pull-out slotof the main body) is kept even in the presence of an external forceapplied to the display element, thereby strongly keeping the integrationwith the main body. According to this imaging device, shooting can beperformed with one hand holding the main body and the display elementcan be easily rolled up when stored.

According to an imaging device of a ninth aspect of the invention, inthe seventh aspect, the flatness keeping mechanism is a back platecovering the back side of the display element, the back plate comes intocontact with the back side of the display element when the displayelement is rolled up, and at least a central portion of the back plateis separated from the display element to support the display element ina flat shape when the display element is unfurled, a pull-out slot forthe display element of the main body is formed to have a shape which isflattened by a predetermined amount from a cross-sectional shape of theunrolled back plate, and to have a clearance formed on a portion facinga surface of the display element.

According to the imaging device of the ninth aspect of the invention,the clearance of the pull-out slot of the main body does not bring thesurface of the display element into contact with the pull-out slot,thereby preventing scratches. Further, the back plate is flattened bythe pull-out slot to about a half, so that a resistance to a rollingmovement can be reduced. Since the back plate is not completelyflattened, it is possible to prevent the display element from easilyshaking.

According to an imaging device of a tenth aspect of the invention, inthe seventh aspect, the flatness keeping mechanism is a back platecovering the back side of the display element, the back plate comes intocontact with the back side of the display element when the displayelement is rolled up, and at least a central portion of the back plateis separated from the display element to support the display element ina flat shape when the display element is unfurled, a pull-out slot forthe display element of the main body is formed to have a shape which isflatter than a cross-sectional shape of the unrolled back plate, and tohave a clearance formed on a portion facing a surface of the displayelement.

According to the imaging device of the tenth aspect of the invention,the clearance of the pull-out slot of the main body does not bring thesurface of the display element into contact with the pull-out slot,thereby preventing scratches. Further, since the back plate is flattenedby the pull-out slot, a resistant to a rolling movement is reduced.

According to an imaging device of an eleventh aspect of the invention,in the seventh aspect, the flatness keeping mechanism is a back platecovering the back side of the display element, the back plate comes intocontact with the back side of the display element when the displayelement is rolled up, and at least a central portion of the back plateis separated from the display element to support the display element ina flat shape when the display element is unfurled, a pull-out slot forthe display element of the main body is formed to have a shape which issubstantially identical to a cross-sectional shape of the unrolled backplate, and to have a clearance expanding toward the center, which isformed on a portion facing a surface of the display element.

According to the imaging device of the eleventh aspect of the invention,the clearance of the pull-out slot of the main body does not bring thesurface of the display element into contact with the pull-out slot,thereby preventing scratches. Additionally, the bent portion of the backplate is not flattened by the pull-out slot and thus the positionalrelationship between the main body and the display element can be kept.When the main body is held, the shape of a base (near the pull-out slotof the main body) is kept even in the presence of an external forceapplied to the display element, thereby strongly keeping the integrationwith the main body. According to this imaging device, shooting can beperformed with one hand holding the main body and the display elementcan be easily rolled up when stored. Moreover, even when the displayelement is slightly bent, the clearance expanding toward the centerprevents rubbing on the display surface, thereby preventing scratches.

A portable equipment of a twelfth aspect of the invention, in the secondto sixth aspects, further includes a pull-out slot for the displayelement on the main body of the portable equipment, the pull-out slotbeing formed to have a shape which is substantially identical to across-sectional shape of the unrolled back plate, and to have aclearance formed on a portion facing a surface of the display element.

According to the portable equipment of the twelfth aspect of theinvention, the clearance of the pull-out slot of the main body does notbring the surface of the display element into contact with the pull-outslot, thereby preventing scratches. Additionally, the bent portion ofthe back plate is not flattened by the pull-out slot and thus thepositional relationship between the main body and the display elementcan be kept. When the main body is held, the shape of a base (near thepull-out slot of the main body) is kept even in the presence of anexternal force applied to the display element, thereby strongly keepingthe integration with the main body. According to this portableequipment, shooting can be performed with one hand holding the main bodyand the display element can be easily rolled up when stored.

A portable equipment according to a thirteenth aspect of the invention,in the second to sixth aspects, further includes a pull-out slot for thedisplay element on the main body of the portable equipment, the pull-outslot being formed to have a shape which is flattened by a predeterminedamount from a cross-sectional shape of the unrolled back plate, and tohave a clearance formed on a portion facing a surface of the displayelement.

According to the portable equipment of the thirteenth aspect of theinvention, the clearance of the pull-out slot of the main body does notbring the surface of the display element into contact with the pull-outslot, thereby preventing scratches. Further, the back plate is flattenedby the pull-out slot to about a half, so that a resistance to a rollingmovement can be reduced. Since the back plate is not completelyflattened, it is possible to prevent the display element from easilyshaking.

A portable equipment according to a fourteenth aspect of the invention,in the second to sixth aspects, further includes a pull-out slot for thedisplay element on the main body, the pull-out slot being formed to havea shape which is flatter than a cross-sectional shape of the unrolledback plate, and to have a clearance formed on a portion facing a surfaceof the display element.

According to the portable equipment of the fourteenth aspect of theinvention, the clearance of the pull-out slot on the main body of theportable equipment does not bring the surface of the display elementinto contact with the pull-out slot, thereby preventing scratches.Further, since the back plate is flattened by the pull-out slot, aresistant to a rolling movement is reduced.

A portable equipment according to a fifteenth aspect of the invention,in the second to sixth aspects, further includes a pull-out slot for thedisplay element on the main body of the portable equipment, the pull-outslot being formed to have a shape which is substantially identical to across-sectional shape of the unrolled back plate, and to have aclearance expanding toward the center, the clearance being formed on aportion facing a surface of the display element.

According to the portable equipment of the fifteenth aspect of theinvention, the clearance of the pull-out slot of the main body does notbring the surface of the display element into contact with the pull-outslot, thereby preventing scratches. Additionally, the bent portion ofthe back plate is not flattened by the pull-out slot and thus thepositional relationship between the main body and the display elementcan be kept. When the main body is held, the shape of a base (near thepull-out slot of the main body) is kept even in the presence of anexternal force applied to the display element, thereby strongly keepingthe integration with the main body. According to this imaging device,shooting can be performed with one hand holding the main body and thedisplay element can be easily rolled up when stored. Moreover, even whenthe display element is slightly bent, the clearance expanding toward thecenter prevents rubbing on the display surface, thereby preventingscratches.

An imaging device according to a sixteenth aspect of the invention, inthe seventh to eleventh aspects, further includes a detecting devicewhich detects a movement of the display element, wherein operation modesare switched in synchronization with the movement of the display elementfrom a first position to a second position.

According to the imaging device of the sixteenth aspect of theinvention, the operation modes can be switched between OFF and ON insynchronization with a change of the display element between a storedstate and a pull-out state. Since the imaging device is turned on/off inresponse to the pulling out/storage of the display element, highoperability can be obtained.

An imaging device according a seventeenth aspect of the invention, inthe seventh to eleventh and sixteenth aspects, further includes convexportions provided on portions of the back plate, which are folded toboth ends of a display screen.

According to the imaging device of the seventeenth aspect of theinvention, the convex portions are provided on portions of the backplate, which are folded to the ends of a screen. Thus the convexportions act as spacers when the display element is rolled up, therebypreventing scratches and rubbing on the display screen of the displayelement.

An imaging device according to an eighteenth aspect of the invention, inthe seventh to eleventh, sixteenth, and seventeenth aspects, furtherincludes a rolling detecting switch disposed on a position makingcontact with a portion outside a display range of the display elementwhen the display element is rolled up, on a roll-up shaft of the displayelement stored in the main body, wherein the rolling detecting switchturns off at least a part of display on a display part when the displayelement is rolled up.

According to the imaging device of the eighteenth aspect of theinvention, when the display element is rolled up around the roll-upshaft, the rolling detecting switch is provided on a position makingcontact with a portion outside the display range, and at least one ofthe display and the power supply is turned off when the display elementis rolled up, so that at least one of the power supply and the displaycan be automatically turned off. Thus it is possible to prevent a skipof power shutdown and excessive power consumption.

In order to attain the object, a portable equipment according to anineteenth aspect of the invention includes a back plate on the backside of a flexible display element, the back plate being bent with acentral portion separated from the display element due to a bend whenthe display element is unfurled, and is closer to the display elementwhen the display element is stored than when the display element isunfurled, wherein the back plate includes a reflective surface on thedisplay element side of the back plate, and light emitting elementsbetween the reflective surface and the display element.

According to the portable equipment of the nineteenth aspect of theinvention, the back plate that is bent when unfurled is provided on theback side of the flexible display element, wherein the reflectivesurface is provided on the inner surface of the back plate and the lightemitting elements are provided between the reflective surface and thedisplay element. Thus it is possible to provide a display element havinghigh compactifying efficiency, in which a back plate can also act as areflecting mirror of backlights.

According to a portable equipment of a twentieth aspect of theinvention, in the nineteenth aspect, the light emitting elements areprovided on an intermediate position of the display element and thereflective surface by means of an elastic member, and the light emittingelements can be rolled in contact with the display element when thedisplay element is rolled up.

According to the portable equipment of the twentieth aspect of theinvention, the light emitting elements are provided on the intermediateposition between the display element and the reflective surface by meansof the elastic member, thereby improving light emitting characteristics.

According to a portable equipment of a twenty-first aspect of theinvention, in the twentieth aspect, the elastic member is a flexibleprinted board having an interconnection of the light emitting elements.

According to the portable equipment of the twenty-first aspect of theinvention, the flexible printed board also acts as the elastic member.Thus the light emitting elements can be provided on the intermediatepoint with a simple configuration.

According to a portable equipment of a twenty-second aspect of theinvention, in the nineteenth to twenty-first aspects, the back platecomes into contact with the display element when the display element isrolled up, and the back plate is ridged to have a plurality of bentportions separate from the display element due to bends when the displayelement is unfurled.

According to the portable equipment of the twenty-second aspect of theinvention, more even backlights can be obtained.

According to the display element, portable equipment, and the imagingdevice of the present invention, the back plate is provided on the backside of the display element, which comes into contact with the back sideof the display element when the display element is rolled up, andsupports the display element in a flat shape by separating from thedisplay element at its central portion, at least, when the displayelement is unfurled. Thus it is possible to provide a flexible displayelement, portable equipment, and an imaging device which have highportability, ease of rolling, and retention of flatness during periodsof use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an outside drawing showing a display device including aflexible display element according to a first embodiment;

FIG. 2 is an explanatory drawing showing the internal configuration ofthe main body of the display device shown in FIG. 1;

FIG. 3 shows a state in which the display element of the display deviceof FIG. 1 is rolled up around a roll-up shaft;

FIG. 4 is a sectional view showing the main body of the display deviceshown in FIG. 1;

FIGS. 5A to 5D are sectional views showing the display element and aback plate shown in FIG. 1;

FIG. 6 is a perspective view showing the back plate of the displaydevice shown in FIG. 1;

FIG. 7 is an explanatory drawing showing the configuration of a roll-upspring;

FIG. 8 is an outside drawing showing a display device including aflexible display element according to a second embodiment;

FIG. 9 is a perspective view showing the display element of the displaydevice shown in FIG. 8;

FIGS. 10A and 10B are sectional views showing the display element andthe back plate of the display device shown in FIG. 8;

FIG. 11 is an enlarged view mainly showing the display element of thedisplay device shown in FIG. 8;

FIG. 12 is a sectional view showing the main body of the display deviceshown in FIG. 8;

FIGS. 13A to 13C are explanatory drawings showing a flexible displayelement according to a third embodiment;

FIG. 14 is an outside drawing showing a display device including aflexible display element according to a fourth embodiment;

FIG. 15 shows a state in which an operation part is provided on theroll-up shaft of the display device shown in FIG. 14;

FIG. 16 shows a state in which the display element of FIG. 14 is rolledup around the roll-up shaft;

FIG. 17 is an explanatory drawing showing a flexible display elementaccording to a fifth embodiment;

FIG. 18 is a perspective view showing the display element of FIG. 17;

FIG. 19 is a rear view showing the display element of FIG. 18;

FIG. 20 is a sectional view showing a back plate shown in FIG. 19;

FIG. 21 is a sectional view showing the display element and the backplate of FIG. 18;

FIG. 22 is a perspective view showing the display device of FIG. 17 inwhich the display element is stored in the main body of the displaydevice;

FIG. 23 is a development for explaining that the back plate of FIG. 17is flattened;

FIG. 24 is a rear view showing the back plate of FIG. 23;

FIG. 25 is a sectional view showing the display element and the backplate of FIG. 24;

FIG. 26 is a front perspective view in which the same configuration asthe display device is applied to an imaging device;

FIG. 27 is a rear perspective view showing the imaging device of FIG.26;

FIG. 28 is a perspective assembly drawing showing the imaging device ofFIG. 26;

FIG. 29 is a perspective view showing a display element and a back platewhich are applied to the imaging device of FIG. 26;

FIG. 30 is a perspective view showing a state in which the displayelement of FIG. 29 is rolled up around a roll-up shaft;

FIG. 31 is an explanatory drawing showing an operation state of theimaging device of FIG. 26;

FIG. 32 is an explanatory drawing showing a state in which the displayelement is pulled out of the main body of the imaging device shown inFIG. 26;

FIG. 33 is a rear perspective view showing the imaging device of FIG.32;

FIG. 34 is an explanatory drawing showing an operation state of theimaging device of FIG. 33;

FIG. 35 is a block diagram showing the configuration of the imagingdevice of FIG. 26;

FIG. 36 is a flowchart showing an example of the operating procedure ofthe imaging device shown in FIG. 26;

FIG. 37 is an outside drawing showing a display device including aflexible display element according to a sixth embodiment;

FIG. 38 is an explanatory drawing showing a state in which the displayelement is pulled out of the main body of the display device shown inFIG. 37;

FIG. 39 is an explanatory drawing showing a motor for rolling andunrolling the display element of FIG. 38;

FIG. 40 is a flowchart showing an example of the operating procedure ofthe display device shown in FIG. 38;

FIG. 41 is a block diagram showing the configuration of the displaydevice of FIG. 38;

FIG. 42 is a block diagram showing a configuration in which the displaydevice of FIG. 38 is applied to an imaging device;

FIGS. 43A to 43D are explanatory drawings showing the shapes of thepull-out slot of the display device shown in FIG. 38;

FIG. 44 is a perspective view of a display element including a backplate having backlights;

FIGS. 45A and 45B are sectional views showing the display element ofFIG. 44;

FIG. 46 is a block diagram showing the configuration of an imagingdevice including the display element of FIG. 44;

FIG. 47 is a perspective view of a display element including a backplate having backlights according to another embodiment;

FIGS. 48A and 48B are sectional views showing the display element ofFIG. 47;

FIG. 49 is a perspective view of a display element including a backplate having backlights according to another embodiment;

FIGS. 50A and 50B are sectional views showing the display element ofFIG. 49;

FIGS. 51A to 51F are explanatory drawings showing back plates accordingto another embodiment;

FIGS. 52A and 52B are explanatory drawings showing a back plateaccording to another embodiment; and

FIGS. 53A and 53B show the cross-sectional shapes of another embodimentof FIGS. 52A and 52B when rolled and unrolled.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following will describe preferred embodiments of a display element,portable equipment, and an imaging device of the present invention inaccordance with the accompanying drawings.

First, a number of flexible displays (e.g., organic EL displays)including flexible display elements have been proposed in which a resin,and so on, is used as a base material instead of a glass of the relatedart.

FIG. 1 is an outside drawing showing a display device (portableequipment) 12 including such a flexible display element 10 according toa first embodiment. In FIG. 1, the strip-like display element 10 ispulled out of a cylindrical main body 14. FIG. 2 shows the internalconfiguration of the main body 14 and a developed state of a roll-upshaft 16 for rolling up the display element 10 and the unrolled displayelement 10. FIG. 3 also shows the roll-up shaft 16 and the displayelement 10 having been completely rolled around the roll-up shaft 16.

As shown in FIG. 4, the main body 14 of FIG. 1 is made up of acylindrical body 14A having open ends, and caps 14B for closing the openends of the cylindrical body 14A. The roll-up shaft 16 is disposedbetween the caps 14B so as to rotate via a bearing portion 14C, and isurged in a rolling direction by a roll-up spring 18 (see FIG. 7).Further, the state of the unrolled display element 10 is kept by astopper (not shown).

As shown in FIG. 5A, the display element is shaped like a thin plate incross section. Portions B on the longitudinal ends of the displayelement 10 include the bent portions 20 substantially bent intoU-shapes. On the back side of the display element 10, a back plate 22having a free shape (when an external force is removed) of FIG. 6 isattached. The back plate 22 is formed by, as shown in FIG. 5B,connecting flat portions 24 of portions C on the longitudinal ends ofthe display element via a curved portion 26. By connecting the two flatportions 24 to the curved portion 26, the flexibility of the flatportions 24 is restricted and the surfaces of the flat portions 24 arekept in parallel with each other. The flat portions 24 are fit into andcombined with the bent portions 20 of the display element 10 shown inFIG. 5A, so that a cross-sectional shape in FIG. 5C is obtained. At thismoment, the flat portions 24 are pressed to the back side of the displayelement 10 by the bent portions 20 and the flat portions 24 are kept inparallel with each other as described above. Thus the overall displayelement 10 is kept flat and the display element 10 pulled out of themain body 14 independently keeps the flatness as shown in FIG. 1 or 2.

In this state, even when an attempt is made to bend the display element10 to the direction along arrows A of FIG. 2 (or in the oppositedirections: in such a direction that the display element 10 is bentalong the width), the display element 10 cannot be easily bent because aforce of the back plate 22 is applied to keep the flatness. Therefore,the display device 12 can be used by holding the main body 14 only withone hand, without holding the display element 10.

The following is an operation of rolling up the display element 10.

When the display element 10 is rolled up, the back plate 22 is flattenedat portions A of FIG. 2 by the roll-up shaft 16 and the curved shape iscorrected to a flat shape in cross section as shown in FIG. 5D. Thus thetwo flat portions 24 are connected via a plane and the force keeping theflatness of the display element 10 is not applied. Therefore, thedisplay element 10 can be easily bent to the direction along the arrowsA (or in the opposite directions) of FIG. 2 and can be easily rolled uparound the roll-up shaft 16. The display element 10 rolled thus isstored in the main body 14 as shown in FIG. 4.

According to the first embodiment, the flexible display element 10 canbe used after being unrolled (pulled out) from the main body 14. Theunrolled display element 10 keeps its flat shape with the flatnessretaining action of the back plate 22. When the display device 12 iscarried, the display element 10 can be stored in the main body 14 asdescribed above.

FIG. 8 is an outside drawing showing a display device (portableequipment) 112 including a flexible display element 110 according to asecond embodiment. The FIG. 8 shows the state that the display element110 is unrolled. FIG. 9 shows the single unit configuration of thedisplay element 110. Over the opposite side of a display surface 110A,convex beam members 126 are bonded as shown in FIG. 11. With thisconfiguration, the flexible display element 110 alone can be bent indirection D (and in the opposite direction) of FIG. 9 but cannot be bentin direction E (and in the opposite direction).

As shown in FIG. 12, a main body 114 is made up of a cylindrical body114A having open ends, and caps 114B for closing the open ends of thecylindrical body 114A. A roll-up shaft 116 is disposed between the caps114B so as to rotate via a bearing portion 114C and is urged in arolling direction by a roll-up spring 118. Further, the state of theunrolled display element 110 is kept by a stopper (not shown).

A back plate 122 combined with the display element 110 has a free-shape(when an external force is removed) of FIG. 10A, and bent portions 124are formed on both longitudinal ends of the display element. When thebent portions 124 are used to combine the back plate 122 with thedisplay element 110 of FIG. 9, the back plate 122 has a curved shape incross section as shown in FIG. 10B. At this moment, from the state ofFIG. 10A, the back plate 122 is extended and combined with the displayelement, so that lateral pressures indicated by arrows B of FIG. 10B areapplied from the back plate 122 in the width direction of the displayelement 110. The lateral pressures are received by the beam members 126bonded on the back side of the display element 110, so that the displayelement 110 keeps the cross-sectional shape of FIG. 10B. Thus a forcefor keeping the flat shape is generated on the flexible display element110 having been pulled out of the main body 114 of FIG. 8. In this way,the display element 110 pulled out of the main body 114 independentlykeeps its flatness. Also, one of the bent portions 124 of the back plate122 may be fixed on the back side of the display element 110.

In this state, even when an attempt is made to bend the display element110 to the direction along the arrows D and E of FIG. 9 (or in theopposite directions), the display element 110 cannot be easily bentbecause a force of the back plate 122 is applied to keep the flatness.Therefore, the display device 112 can be used by holding the main body114 only with one hand, without holding the display element 110.

The following is an operation of rolling up the display element 110.

As in the first embodiment, when the display element 110 is rolled up,the back plate 122 is flattened by the roll-up shaft 116 because thedisplay element 110 is rolled up around the roll-up shaft 116, and thecurved shape of the back plate 122 is corrected to a flat shape. Whenthe back plate 122 is flattened thus, the lateral pressures applied tothe flexible display element 110 are released. Thus the display element110 can be bent along the arrow D (or in the opposite direction).Therefore, the display element 110 is smoothly rolled up around theroll-up shaft 116. The display element 110 rolled thus is stored in themain body 114 as shown in FIG. 12.

As described above, according to the second embodiment of the presentinvention, the flexible display element 110 is used after being pulledout from the main body 114 and the unrolled (pulled-out) display element110 keeps its flat shape alone. When carried, the display element 110can be rolled up and thus can be stored in the main body 114.

FIG. 13A shows a display device 212 including a flexible display element210 according to a third embodiment. FIG. 3 is a sectional view showinga back plate 222 combined with the display element 210. FIG. 13B is asectional view showing the rolled display element 210. On thelongitudinal ends of the back side of the display element 210,protruding pins 228 are disposed at a predetermined spacing along thelongitudinal direction. Further, on the longitudinal ends of the backplate 222, long holes 230 are formed at the same spacing as the pins228. The long holes 230 are formed along a direction (width direction)orthogonal to the longitudinal direction.

When the back plate 222 is attached to the display element 210 byfitting the pins 228 over the long holes 230, the long holes 230 pressthe pins 228 in the direction orthogonal to the longitudinal directionin the state of FIG. 13A where an external force is not applied to theback plate 222. Thus lateral pressures are applied to the displayelement 210. On the other hand, in FIG. 13B where the back plate 222 isflattened, the pressing forces are eliminated and thus the lateralpressures are released, so that the display element 210 can be rolledup. FIG. 13C is a rear view showing the display element 210 of thedisplay device 212. In FIG. 13C, lateral pressures are applied to thedisplay element 210.

In this way, the display element 210 is integrated with the back plate222 by applying lateral pressures from the longitudinal ends in thewidth direction, and a raised part is formed at the center of the backplate 222. Thus the overall display device 212 has stereoscopic shapeand is not easily bent even by a bending force, so that the displayelement 210 keeps the flat shape.

FIG. 14 is an outside drawing showing a display device 312 including aflexible display element 310 according to a fourth embodiment. Thedisplay element 310 is unrolled. FIG. 15 shows the single unitconfiguration of the display element 310. In FIG. 15, on the back sideof the display element 310, a back plate 322 indicated by broken linesis bonded on a bonding portion 330 shaded by diagonal broken lines. Asshown in FIG. 15, a roll-up shaft 316 also acts as a main body having anoperation part 332 and a power switch 334.

The back plate 322 to be combined with the display element 310 issubstantially V-shaped in its free shape (when an external force isremoved). When the back plate 322 is combined with the display element310, the back plate 322 is extended from the V-shape as shown in FIGS.14 and 15. At this moment, the back plate 322 is combined while beingextended. Thus a folded end 336 on the opposite side from the bondingportion 330 applies a lateral pressure to the display element 310 andthe lateral pressure is accepted by the stiffness of the display element310, so that the flatness of the display element 310 is kept and a forcefor keeping the flat shape is generated on a part unrolled from theroll-up shaft 316 of FIG. 15. With this configuration, the displayelement 310 unrolled from the roll-up shaft 316 independently keeps itsflatness.

In this state, even when an attempt is made to bend the display element310, the display element 310 cannot be easily bent because a force ofthe back plate 322 is applied to keep the flatness. Therefore, thedisplay device 312 can be used by holding the roll-up shaft 316 onlywith one hand, without holding the display element 310.

The following is an operation of rolling up the display element 310.

When the display element 310 is rolled up, rolling is performed from theside of the roll-up shaft 316 (main body) as shown in FIG. 14. Thus theback plate 322 is flattened by the roll-up shaft 316 and the curvedshaped is corrected to a flat shape as in the first embodiment. The backplate 322 flattened thus releases the lateral pressure applied to thedisplay element 310 and thus the display element 310 can be bent andsmoothly rolled up around the roll-up shaft 316. The display element 310rolled thus is rolled up around the roll-up shaft 316 as shown in FIG.16.

As described above, according to the fourth embodiment, the flexibledisplay element 310 is used after being unrolled from the roll-up shaft316. The display element 310 can keep its flat shape alone and whencarried, the display element 310 can be stored while being rolled uparound the roll-up shaft 316. Thus the display device 312 can have highportability and operability. Reference numeral 338 denotes a pull forunrolling the display element 310. When the display element 310 isrolled up, the pull 338 acts as a holding portion that is pressed to thearc-shaped back plate 322 to keep the shape of the back plate 322.

FIG. 17 is an outside drawing showing a display device 412 including aflexible display element 410 according to a fifth embodiment. In FIG.17, the display element 410 is unrolled (pulled out) from a main body414. FIG. 18 shows the single unit configuration of the display element410. FIG. 19 shows the back side of the display element 410. FIG. 20 isa sectional view of a back plate 422. In FIGS. 18 and 19, the displayelement 410 has a predetermined thickness. The back plate 422 has aplurality of notches 442 formed to prevent convex portions 440 formed onboth end portions for applying lateral pressures from causingresistances when the display element 410 is rolled up.

In the configuration of the display element 410, it is needless to saythat as long as beam members 126 are bonded over the opposite side of adisplay surface as shown in FIG. 9, it is possible to prevent thedisplay element 410 from being bent even by lateral pressures applied bythe back plate 422 as shown in FIG. 21. Moreover, the configuration isnot particularly limited as long as the display element 410 is designedto have strength against a bend to be resistant to the lateral pressuresof the back plate 422, thus the display element may have a flat shape.

FIG. 22 is an outside drawing showing the display element 410 rolled uparound a roll-up shaft 416 of the main body 414. FIGS. 23 and 24 aredevelopments for explaining the state of the display element 410 and theback plate 422 in the main body 414 at this moment. Since the displayelement 410 is rolled up around the roll-up shaft 416 of the main body414, the back plate 422 is crushed and flattened. Thus the lateralpressures for keeping the flatness of the display element 410 are notapplied to the display element 410.

The cross-sectional shape at this moment is illustrated in FIG. 25.Since the folded portions 440 of the back plate 422 are separated fromboth ends of the display element 410, the lateral pressures arereleased. FIGS. 23 and 24 show virtual shapes. When the display element410 is unrolled as shown in FIGS. 23 and 24, the back plate 422 is bentand the lateral pressures are applied to the display element 410 (seeFIGS. 18 and 19).

FIG. 26 is a front perspective view in which the same configuration asthe display device of the present invention is applied to an imagingdevice (digital camera) 500. FIG. 27 is a rear perspective view of theimaging device 500. A main body 502 is substantially shaped like apartially cut square pole. In the rear view, a pull-out slot of thedisplay element is formed on the left (the pull-out slot is closed by alid 504 fixed on an end of the display element and thus is not shown inFIGS. 26 and 27). The lid 504 has a pull 506 formed to pull out thedisplay element.

A retractable flash 508 capable of protruding and retracting is providedon the top surface of a main body 502, a taking lens 510 is provided atthe front of the upper part of the main body 502, a grip 512 is formedunder the taking lens 510, and a release button 514 is disposed near theupper end of the grip 512.

Further, a zoom lever 515 is disposed on the upper part of the back ofthe main body 502, a direction key 518 is disposed under the zoom lever515, selecting buttons 520, 522 and 524 are provided near the pull-outslot (not shown), and indications showing operations and functionscorresponding to these buttons 520 to 524 are engraved beside thebuttons.

The buttons 520, 522 and 524 have a plurality of functions. When thedisplay element is pulled out, the names of the functions (e.g., ON andOFF in FIG. 33) are displayed on the display element so as to be closeto the buttons. By pressing the selecting buttons 520, 522 and 524 atthis moment, the functions displayed on the display element areperformed instead of the engraved functions. Although the displayelement 110 of FIG. 8 is illustrated in the following explanation, thedisplay elements of FIGS. 1 to 25 are all applicable to the imagingdevice.

FIG. 28 is an assembly drawing showing the internal configuration of theimaging device 500. The display element (flexible display) 110 is rolledup around a roll-up shaft 516 disposed in the lower part of the mainbody 502, and a lens unit 526 is disposed in a space above the roll-upshaft 516. On the lens unit 526, a retractable flash unit 528 isdisposed. A main substrate 530 is disposed on the back side of theimaging device and a battery (not shown) is stored in an expanded partat the front of the grip.

The rolled flexible display 110 is shaped like a cylinder as shown inFIG. 30. When the flexible display 110 is unrolled as shown in FIG. 29,the flat shape is kept by the actions of lateral pressures applied bythe back plate.

When the imaging device 500 is used, as shown in FIG. 31, a user holdsthe pull 506 with the left hand and pulls out the display element 110while holding the main body 502 with the right hand. The roll-up shaft516 of the display element 110 is urged in the rolling direction by theroll-up spring 18 shown in FIG. 7. When the display element 110 isunrolled to a predetermined position, the roll-up shaft 516 is locked bya roll-up shaft locking mechanism 531 (see FIG. 35) made up of a knownlatching/unlatching mechanism, and the imaging device 500 enters a stateof FIGS. 32 and 33. In this state, the display element 110 is not rolledback even when the user moves the left hand off the pull 506. When arolling detecting SW 533 (see FIG. 35) for detecting the rotation of theroll-up shaft 516 detects that the display element 110 has beencompletely pulled out of the main body 502, power is supplied to animaging circuit by the action of a rolling detecting circuit 535 (seeFIG. 35) of the main substrate 530, and then the taking lens 510protrudes from a retraction position to a shooting position shown inFIG. 32. Power is supplied thus when the display element 110 iscompletely pulled out, thereby increasing immediacy for the imagingdevice 500 applied to a camera.

Further, the retractable flash 508 pops up concurrently with theoperation of the taking lens 510 and a light emitting portion 509 isexposed as shown in FIG. 32. Next, when the imaging circuit is activatedand a live-view image is outputted, the live-view image of a subject isdisplayed on the display surface of the display element 110 as shown inFIG. 33, enabling framing and other operations for photo shooting. Atthis moment, the flat shape of the display element 110 is kept by theback plate 122 and the pull-out slot of the main body 502 restricts thepositional relationship relative to the main body 502. Thus the displayelement 110 can be independently stabilized in a state in which the mainbody 502 is held with one hand as shown in FIG. 34, and the positionalrelationship and the flat shape of FIG. 34 can be kept even when anexternal force is applied. Therefore, the operations of the imagingdevice, i.e., shooting, reproduction, edition and so on can be performedwith one hand having held the main body 502 without holding the displayelement 110, so that operability improves when the imaging device 500 isapplied to a camera.

When the display element 110 is stored in the main body 502, in responseto the pull 506 strongly pulled in a pulling direction from the state ofFIG. 32, the roll-up shaft 516 having been locked by the roll-up shaftlocking mechanism 531 is unlocked and the display element 110 is rolledup around the roll-up shaft 516.

When the rolling detecting switch 533 for detecting the rotation of theroll-up shaft 516 detects that the display element 110 has beencompletely rolled up around the roll-up shaft 516, the operation of theimaging circuit is stopped by the action of the control circuit of themain substrate 530, the taking lens 510 is moved from the shootingposition to the retraction position, the image device enters the stateof FIG. 26 (protected by a barrier), and then the power is turned off.Further, the flash 508 is also stored in the main body 502 concurrentlywith the retracting operation of the taking lens 510. In this way, thepower is turned off concurrently with the rolling movement of thedisplay element 110, so that an operation for turning off the power canbe omitted and thus the inconvenience can be eliminated. Moreover,portability remarkably increases when the imaging device 500 is appliedto a camera.

FIG. 35 is a block diagram showing the configuration of the imagingdevice 500.

A diaphragm device 532 is disposed behind the taking lens 510 of theimaging device 500, and a CCD 534 is disposed on the image formingposition of the taking lens 510. The overall operation of the imagingdevice 500 is controlled by a CPU 536. The CPU 536 acts as a systemcontrolling circuit which controls a camera system according to apredetermined program and also acts as an arithmetic device whichperforms various operations such as autoexposure (AE) operation,autofocus (AF) operation, and white balance (WB) adjustment operation.

A program run by the CPU 536, kinds of data required for control, and soon are stored in a ROM 538 connected to the CPU 536. CCD pixel defectinformation, kinds of constant/information about camera operations, andso on are stored in an EEPROM 540.

A memory 544 connected to the CPU 536 via a bus 542 is used as theexpansion area of the program and the arithmetic area of the CPU 536 andalso used as a temporary storage area of image data and audio data. Astorage part 546 is a temporary memory only for image data.

The release button 514 is an operation button for inputting aninstruction to start shooting and is a two-step stroke switch which ismade up of an S1 switch turned on by a half press and an S2 switchturned on by a full press.

The display element 110 is driven as an electronic view finder fordisplaying through images during shooting and is also driven as an imageproduction monitor for displaying still images and moving images duringreproduction. Further, the display element 110 is also used as a displayscreen for a user interface. Menu information and information aboutselected items and setting contents are displayed on the display element110 when necessary. Moreover, image data stored in the storage part 546is reduced and displayed as thumbnail images on the display element 110.

The main body 502 has a medium socket 548 in which a recording medium550 is loaded. The type of recording medium 550 is not particularlylimited. Various media including xD-PictureCard, a semiconductor memorycard typified by SmartMedia (trademark), a portable and compact harddisk, a magnetic disk, an optical disk, and a magneto-optical disk canbe used.

The media controller 552 performs necessary signal conversion to passinput/output signals suitably for the recording medium 550 loaded in themedium socket 548.

Further, the imaging device 500 includes a communication circuit 556 forconnection to a personal computer and other peripheral equipment via aconnector or an antenna 554. Reference numeral 558 denotes a switch forturning on/off an image displayed on the display element 110, andreference numeral 560 denotes a display element driving circuit fordriving the display element 110. Reference numeral 562 denotes a powersupply circuit through which power is supplied to the CPU 536 from apower supply device 564 such as a battery and so on.

The following will discuss the camera function of the imaging device500.

Zoom control, focus control, and iris control are performed on thetaking lens 510 and the diaphragm device 532 by an exposure controlcircuit 566, a distance-measurement control circuit 568, azoom/retraction control circuit 570, and a lens extension/retractionconfirming circuit 572 which are controlled by the CPU 536.

Light having passed through the taking lens 510 forms an image on thelight-receiving surface of the CCD 534. A number of photodiodes (lightreceiving elements) are arranged in a two-dimensional manner on thelight receiving surface of the CCD 534, and primary-color filters of red(R), green (G), and blue (B) are so disposed as to correspond to thephotodiodes in a predetermined arrangement. Further, the CCD 534 has anelectronic shutter function of controlling the charge storage time(shutter speed) of each photodiode. The CPU 536 controls the chargestorage time in the CCD 534 through a timing generator 574. Imagingelements of other types such as a MOS may be used instead of the CCD534.

A subject image formed on the light receiving surface of the CCD 534 isconverted into signal charge by the photodiodes according to an amountof incident light. The signal charge having been accumulated in thephotodiodes is read sequentially as voltage signals (image signals)corresponding to the signal charge based on a driving pulse applied fromthe timing generator 574 in response to an instruction of the CPU 536.

Signals outputted from the CCD 534 are transmitted to an analogprocessing section, in which RGB signals of each pixel are sampled andheld (correlated double sampling) before being amplified. After that,the signals are applied to an AD converter 576. The RGB signals havingbeen converted into digital signals by the AD converter 576 in a dotsequential manner are stored in an image display memory 580 through amemory control section 578.

The RGB signals having been stored in the image display memory 580 areprocessed by an image processing circuit 582 according to an instructionof the CPU 536. In other words, the image processing circuit 582 acts asan image processing device which includes a synchronization circuit (aprocessing circuit which interpolates a spatial displacement of a colorsignal in a color filter arrangement of a single-panel CCD andsimultaneously converts the color signal), a white balance correctioncircuit, a gamma correction circuit, an edge correction circuit, and aluminance/color signal difference generation circuit. The imageprocessing circuit 582 performs predetermined signal processingaccording to a command from the CPU 536 while using the image displaymemory 580.

RGB image data inputted to the image processing circuit 582 is convertedinto a luminance signal and a color difference signal in the imageprocessing circuit 582 and is subjected to predetermined processing suchas gamma correction and so on. The image data having been processed inthe image processing circuit 582 is stored in the storage part 546.

When a photographed/reproduced image is outputted to the display element110, the image data is read from the storage part 546 and is transmittedto the display element driving circuit 560 through the bus 542. Thedisplay element driving circuit 560 converts the inputted image datainto a signal of a predetermined system for display (for example, anNTSC color combined video signal) (NTSC: National Television SystemCommittee) and outputs the signal to the display element 110. Further, athrough image during shooting is displayed on the display element 110from the image processing circuit 582 through the bus 542 and thedisplay element driving circuit 560.

FIG. 36 is a flowchart showing the control of a series of operations ofthe imaging device 500.

When the rolling detecting switch 533 detects that the display element110 has been completely pulled out (S100), the display element drivingcircuit 560 is turned on (S110). After that, the image display on/offswitch 558 is turned on (S120) and a mode dial (e.g., the selectingbuttons 520, 522 and 524) is operated to select reproduction (S130). Atthis moment, images recorded on the memory 544 and the storage part 546are read and displayed on the display element 110 (S140). When the modedial is operated to select recording (S130), an output image from theimage processing circuit 582 is displayed on the display element 110(S150). Thereafter, at the completion of the operation of the imagingdevice 500, the display element 110 is rolled back into the main body502. When the rolling detecting switch 533 detects that the displayelement 110 has been completely rolled up (S160), the display elementdriving circuit 560 is turned off (S70). The sequence of the imagingdevice 500 is completed thus.

As described above, when the imaging device 500 is applied to a camera,the configuration of FIG. 34 eliminates the need for supporting thedisplay element 110 with one hand while holding the main body 502 withthe other hand, enabling one-hand shooting. A user can freely use theother hand (left hand in the present embodiment) for operations on thescreen, the operations of a taking lens, and so on. Thus it is possibleto achieve a camera having high operability without causinginconvenience.

Further, as shown in FIG. 31, by holding the main body 502 with one handand pulling out the display element 110 with the other hand, the imagingdevice 500 can enter a shooting state. At this moment, the power isturned on and switching to a shooting mode is performed insynchronization with the rolling detecting switch 533, shown in FIG. 35,for detecting rolling and a pulling-out detecting switch (not shown) fordetecting the pulling out of the display element 110, so that theimaging device 500 can enter the shooting state without the need foroperating the power supply or switching modes. It is therefore possibleto achieve a camera enabling excellent snapshots.

FIG. 37 is an outside drawing showing a display device 612 including aflexible display element 610 according to a sixth embodiment. FIG. 37shows a state in which a display element 610 is stored in a main body614, and FIG. 38 shows a state in which the display element 610 ispulled out of the main body 614. The present embodiment illustrates anexample of an image player capable of displaying, on the display element610, image data stored in a built-in memory. FIG. 39 shows the main partof the internal configuration of the image player. A rotating shaft 619of a motor 618 is connected to a roll-up shaft 616, and the displayelement 610 is pulled out and rolled up by electricity. Referencenumeral 620 is a pull attached to an end of the display element 610 andalso acts as a lid for closing a pull-out slot 615 of the main body 614.

A series of operations of the display device 612 will now be describedin accordance with the flowchart of FIG. 40 and the block diagram ofFIG. 41 showing the image player.

When a power switch 622 is slid to the left (to the left when viewedfrom the display surface) in FIG. 37 (S200), it is detected that thepower switch has been turned on, and an image display circuit 626 isturned on by a system controller 624 (S210). Simultaneously, a drivingcircuit 628 is controlled to rotate the motor 618 of FIG. 39 in acounterclockwise direction, and the display element 610 extends outalong the arrow of FIG. 38 (S220). Thus the display screen can beobserved and a menu screen stored in a built-in memory 630 is displayedon the display screen to receive various operations from operationbuttons 632 (S230).

Next, when the power switch is turned off (S240), the motor 618 isrotated clockwise by the system controller 624, and the display element610 is rolled up around the roll-up shaft 616 (S250). Simultaneously,the image display circuit is turned off (S260) and the power switchwaits for an input. The sequence is completed thus. In FIG. 41,reference numeral 634 denotes a connector connected to the systemcontroller 624 via an input/output circuit 636. The connector 634 isconnected to external communication equipment, so that information ispassed between the image player and the external communicationequipment.

FIG. 42 is a block diagram showing an imaging device in which thedisplay element 610 is rolled up by the rolling motor 618 byelectricity. The configuration of the imaging device is substantiallysimilar to that of the imaging device 500 shown in FIG. 35, except forthe motor 618 and the driving circuit 628. Thus the similar parts areindicated by the same reference numerals and the explanation thereof isomitted. Further, the series of operations in reproduction mode conformsto the sequence of FIG. 40.

As shown in FIG. 38, when the display element 610 and a back plate (notshown) are pulled out, the cross-sectional shape of the back plate isrestricted by the shape of the pull-out slot 615 at the base of the mainbody 614.

FIG. 43A shows an example in which a pull-out slot 615A is formed tohave a shape which is substantially identical to the cross-sectionalshape of the unrolled back plate. The pull-out slot 615A formed thus canstrongly keep the flatness of the unrolled display element 610, so thatthe flatness can be more easily kept. On the front side of the displayelement 610, only the outer periphery of the display element 610 and theedge of the pull-out slot 615A come into contact with each other and thecentral portion of the display element 610 does not make contact withthe pull-out slot 615A because of a clearance. Thus the display surfaceis not rubbed and scratches can be prevented.

FIG. 43B shows an example in which a pull-out slot 615B is formed tohave a shape which is flatter than the cross-sectional shape of theunrolled back plate in some small measure. Although the pull-out slot615B formed thus keeps the flatness of the unrolled display element 610less than the pull-out slot 615A of FIG. 43A, a resistance upon rollingis low, so that the display element 610 can be easily stored.

FIG. 43C shows an example in which a pull-out slot 615C is formed tohave a shape which is further flatter than the cross-sectional shape ofthe unrolled back plate. The pull-out slot 615C formed thus reduces aforce required for storing the display element 610, so that the displayelement 610 can be frequently pulled out and stored with highoperability. On the front side of the display element 610, FIG. 43C issimilar to FIG. 43A in that only the outer periphery of the displayelement 610 and the edge of the pull-out slot 615C come into contactwith each other. However, since the clearance increases toward thecentral portion, the display surface is not rubbed and scratches can beprevented even when the display element 610 is somewhat bent.

FIG. 43D shows a pull-out slot 615D formed by combining the restrictedback plate shape of FIG. 43A with the shape having the clearance of FIG.43C.

Since the back plate and the edge of the display element 610 are heldthrough the pull-out slot 615D, the base of the display element 610 ispositioned relative to the main body 614 and the display element 610keeps its protruding shape in a certain direction while keeping itsflatness as shown in FIG. 34. With this configuration, without the needfor holding the display element 610, the display device 612 can be usedas a display device or an imaging device by holding the main body 614with one hand.

FIG. 44 is an outside drawing showing a display element and a back platewhich are applied to the display devices of FIGS. 1, 8 and 15 and theimaging device of FIG. 26.

As shown in FIG. 44, the display device of the present embodimentincludes a flat display element 700 and a back plate 722 that isattached to the back side of the display element 700 and has a curvedshape in cross section. The display element 700 has one end connected toa roll-up shaft 716 and the other end connected to a rod 718, and thusthe display element 700 is hardly bent by a force curving in thedirection of an arrow 1 (or in the opposite direction). On the otherhand, the display element 700 is easily bent by a force curving in thedirection of an arrow 2 (or in the opposite direction), and thus thedisplay element 700 can be rolled up around the roll-up shaft 716 andstored. The back plate 722 is curved and has a cross-sectional shape ofFIG. 45A when unfurled. In this case, a clearance is generated betweenthe display element 700 and the back plate 722 and increases toward thecenter. The display element 700 is a flexible LCD. Since transmittedlight is necessary for viewing displayed images, as shown in FIG. 44, aplurality of LEDs 720 for backlighting are arranged around the center ofthe back plate 722 to transmit light at a distance from the back side ofthe display element 700. A flexible printed board (flexible printedboard for backlighting) 724 having the LEDs 720 is bonded to the backplate 722 and has one end connected to a backlight driving circuit 726of FIG. 46 (not shown in FIG. 44) through the end of the back plate 722.The light beams of the LEDs 720 are radially emitted as shown in FIG.45A. The back plate 722 has a reflective surface on which light beamsemitted in respective directions are reflected to the display element700 as shown in FIG. 45A. Thus the LEDs 720 can be used as backlights.After rolled up, the display element 700 and the back plate 722 have across-sectional shape shown in FIG. 45B. Since the back plate 722substantially becomes flat in cross section, the display element 700 andthe back plate 722 can be rolled up and stored in a small space.

FIG. 46 is a block diagram showing the case where the display element isapplied to an imaging device. The configuration of the imaging device issubstantially similar to that of the imaging device 500 shown in FIG.35, except for the backlight LEDs 720 and the backlight driving circuit726. Thus the similar parts are indicated by the same reference numeralsand the explanation thereof is omitted.

FIG. 47 is an outside drawing showing a display element 810 and a backplate 822 according to another embodiment in which light emittingelements are provided in two rows.

In a display device of the present embodiment, the display element 810has one end connected to a roll-up shaft 816 and the other end attachedto a rod 818, so that the display element 810 is hardly bent in onedirection and is easily bent in the other direction. Further, thedisplay element 810 can be rolled up around the roll-up shaft 816 andstored. The back plate 822 is curved with two ridges 826 as shown inFIG. 48A and has a cross-sectional shape of FIG. 48A when unfurled.Moreover, a plurality of backlight LEDs 820 are arranged in two rowsaround the center of the back plate 822 to obtain more evenlytransmitted light. A flexible printed board (flexible printed board forbacklighting) 824 having the LEDs 820 is bonded to the back plate 822and has one end connected to the backlight driving circuit 726 of FIG.46 through the end of the back plate 822. The bend absorbing portions ofthe flexible printed board are bent in an unfurled state of FIG. 47.When the display element is rolled up and stored, the back plate 822becomes flat and the spacing between the LEDs 820 is increased as shownin FIG. 48B, so that dimensional changes are absorbed by the bentportions. The light beams of the LEDs 820 are radially emitted as shownin FIG. 48A. The back plate 822 has a reflective surface on which thelight beams emitted in respective directions are reflected to thedisplay element 810 that is a flexible LCD as shown in FIG. 48A, so thatthe LEDs are caused to act as backlights. After rolled up, the displayelement 810 and the back plate 822 have a cross-sectional shape shown inFIG. 48B. The back plate 822 substantially becomes flat in crosssection. Thus the display element 810 and the back plate 822 can berolled up and stored in a small space.

FIG. 49 is an outside drawing showing a display element 910 and a backplate 922 according to another embodiment in which light emittingelements are arranged to emit light to the back side.

As shown in FIG. 50A, the back plate 922 of the present embodiment is sobent as to have a second expanded portion 923 at the center of the backplate 922. Further, backlight LEDs 920 are arranged around the center ofthe back plate 922 to emit light to the back plate 922. A flexibleprinted board (flexible printed board for backlighting) 924 having theLEDs 920 is bonded to the back plate 922 with four bonded portions 924Aand has one end connected to the backlight driving circuit 726 of FIG.46 through the end of the back plate 922. The flexible printed board 924is bent with the LEDs 920 disposed at the intermediate position as shownin FIG. 50A, and reflected light is emitted to the back side of thedisplay element 910 through a reflective surface as shown 50A. Whenunfurled, the back plate 922 is bent as shown in FIG. 49. When rolledup, the back plate 922 is flattened and is reduced in thickness as shownin FIG. 50B, so that the display element 910 and the back plate 922 canbe rolled up and stored in a small space. At this moment, the convexportions of the LEDs 920 facing the back side are stored in the secondexpanded portion 923 at the center of the back plate, so that the backplate 922 is not deformed.

The flexible printed board 924 does not always have to keep the shape ofthe display element 910. Any configuration may be used as long as theflexible printed board 924 is bent and separated from the displayelement 910 when used and the flexible printed board 924, when stored,comes into contact with or comes closer to the display element 910 thanwhen used.

FIGS. 51A to 51D show a back plate according to another embodiment. Aback plate 1022 of FIGS. 51A to 51C has two high ridges 1026. A backplate 1122 of FIGS. 51D to 51F has two ridges 1126 bent to be lower thanthe ridges 1026. For convenience, reference numeral 10 denotes a displayelement.

FIGS. 52A and 52B show a back plate according to still anotherembodiment. A back plate 1222 of FIGS. 52A and 52B does not have anyridges or is not substantially V-shaped but substantially has a recessedshape in cross section. FIG. 53A shows the cross-sectional shape of theunrolled display element and the unrolled back plate of FIGS. 52A and52B. FIG. 53B shows the cross-sectional shape of the rolled displayelement and the rolled back plate of FIGS. 52A and 52B.

1. An electronic device comprising a display unit, the display unitcomprising: a flexible display element which displays an image on afront surface thereof; and a member which is placed facing a rearsurface opposite to the front surface of the flexible display element,the member applying tension to the flexible display element when theflexible display element is unfurled.
 2. The electronic device with adisplay unit according to claim 1, wherein the flexible display elementcomprises a plurality of convex beam members on the rear surfacethereof.
 3. The electronic device with a display unit according to claim2, wherein the plurality of convex beam members comprises rod-shapedmembers which are parallel to each other.
 4. The electronic device witha display unit according to claim 2, wherein cross-section surfaces ofthe plurality of convex beam members are trapezoidal.
 5. The electronicdevice with a display unit according to claim 1, wherein the flexibledisplay element and the member are diagonal, wherein the flexibledisplay element comprises a plurality of protruding pins which aredisposed at a predetermined spacing on both ends of the rear surfacealong a longitudinal direction, wherein the member comprises long holesformed at a same spacing as the plurality of protruding pins, andwherein the plurality of protruding pins is fitted over the long holesto attach the member to the flexible display element.
 6. The electronicdevice with a display unit according to claim 5, wherein each of thelong holes is formed to be elongated along a direction orthogonal to thelongitudinal direction.